Polysilazane Precursor Used for Formation of Oxidized Insulator

摘要

We report on SiO_2 film formation using Polysilazane precursor treated with remote oxygen plasma and high-pressure H_2O vapor heating. Polysilazane precursor films with a thickness of 130 nm were spin coated on silicon substrates. They were annealed at 350℃ in remote oxygen plasma at a pressure of 2.0×10~(-2) Pa, frequency of 13.56 MHz and power of 300 W, and then followed by 13-atmospheric-pressure-water vapor heating at 260℃ for 3 hrs. It was found that the films made by Polysilazane precursor were entirely oxidized by high-pressure H_2O vapor thermal treatment, and the densities of Si-N and Si-H bonds inside those films diminished by the combination of double oxidized treatment. While Metal-Oxide-Semiconductor (MOS) capacitors fabricated only by high-pressure H_2O vapor heat treatment had a high specific dielectric constant of 6.1, an oxide charge density of 1.3×10~(12) cm~(-2) and a density of interface trap of 5.4×10~(11) cm~(-2) eV~(-1), the combination of oxygen-plasma-then-water-vapor-thermal oxidized treatment allowed us to reduce them to 4.1, 1.6×10~(11) cm~(-2) and 4.2×10~(10) cm~(-2)eV~(-1), respectively, indicating better SiO_2 dielectric material and SiO_2/Si interface.